Syntax error

[anonymous]

Plugin doesn't seem to work on a regular RHEL 5.4 system, using Python 2.4.3 and running Trac 0.12. It generates this error:

Feb  8 15:51:13 *hostname* Trac[loader] ERROR: Skipping "tracjsgantt = tracjsgantt":  Traceback (most recent call last):   File "/usr/lib/python2.4/site-packages/Trac-0.12-py2.4.egg/trac/loader.py", line 70, in _load_eggs     entry.load(require=True)   File "/usr/lib/python2.4/site-packages/pkg_resources.py", line 1830, in load     entry = __import__(self.module_name, globals(),globals(), ['__name__'])   File "build/bdist.linux-x86_64/egg/tracjsgantt/__init__.py", line 1, in ?     #   File "/usr/lib/python2.4/site-packages/Trac_jsGantt-0.3-py2.4.egg/tracjsgantt/tracjsgantt.py", line 133      return (options[name] if options.get(name) else self.options[name])                             ^ SyntaxError: invalid syntax (tracjsgantt.py, line 133))

I'm using the current SVN code:

$ svn info tracjsgantt/tracjsgantt.py | grep -i rev
Revision: 9844
Last Changed Rev: 9782

[Chris Nelson]

I'm sorry to say I'm running Trac 0.11 and Python 2.5.2 and no good way to try to reproduce your problem.

While I have done some work since the version you reference, the line:

return (options[name] if options.get(name) else self.options[name])

is still there and works fine for me.

​http://en.wikipedia.org/wiki/Ternary_operation#Python notes that the ternary if was added to Python in 2.5. I believe you need a newer Python to use this plugin.

You could try replacing

        def g(name):
            return (options[name] if options.get(name) else self.options[name])

with

        def g(name):
            if options.get(name):
                return options[name]
            else:
                return self.options[name]

(Untested.) but I believe I use the ternary if elsewhere, too.

[osimons]

I just spotted this by accident, but can't help but comment... Why don't you just use the common Python ideom of:

return options.get(name) or self.options[name])

This is the same case that presumes that options.get(name) is defined AND that it evaluates to True by having non-empty content. If you want it to return possibly empty values, the correct way would be to always return it when defined and only resort to some other default value if non-existing:

return options.get(name, self.options[name])
# alternatively
return name in options and options[name] or self.options[name]

Seeing Trac 0.11 even supports Python 2.3, using 2.5 syntax is not recommended. The patterns above is something you'll find in all parts of Trac when needed. The pattern works by the fact that Python will always return the value of the last and so that if several facts evaluates to True the last one is output for further use - and if any evaluates to False the remaining checks are skipped with no danger of things like lookup errors, and instead moving on to evaluate the or argument:

>>> a = 1
>>> a and 'yes' or 'no'
'yes'
>>> a = 0
>>> a and 'yes' or 'no'
'no'

[Chris Nelson]

Replying to osimons:

I just spotted this by accident, but can't help but comment... Why don't you just use the common Python ideom of: ...

Because I have 25+ years programming experience but something like 25 days of it is with Python. Thanks for the tip!

[anonymous]

I was going to make the same "and-or" suggestion, but since it's already been made...

I would be happy to test any modified code if you don't have an available test environment.

[Danny Sauer]

Udiff patch for tracjsgantt.py against SVN version 9849

[Danny Sauer]

Ok, that patch didn't do it. I'm still working. :)

[Danny Sauer]

Patch to make plugin work with Python 2.4

[Danny Sauer]

Ok, I created a working patch: attachment:oldpython.patch​.

I incorporated the earlier partial patch, added some code to handle date time parsing in a way that works with 2.4, and had to modify the _work_time logic to skip milestones (I was getting an invalid key error since milestones don't have estimated hours).

I also tweaked it a little to allow tickets with just predecessors, not successors (in the event someone sets up a custom files instead of using the module which keeps the paired fields in sync), and replaced three tabs with whitespace for indentation consistency. ;)

I'm using this code now, and it works well. I haven't tested start and end dates with it yet, though, and I don't use parent tickets. Hopefully that stuff will just work. /crosses fingers

[Chris Nelson]

(In [10237]) Removed ternary ifs. Refs #8484

[Chris Nelson]

(In [10253]) Changed date handling to be compatible with Python 2.4. Refs #8484